Two rather large sun bursts of charged plasma came shooting out from the sun and headed straight for Earth on September 9th and 10th. These bursts are known as 'solar storms', and can be extremely detrimental to electrical grids, GPS services, etc. Basically, anything of high altitude satellite frequency can be potentially knocked out for up to several months with a strong enough storm.

Luckily, these two storms didn't do a ton of damage. Upon impact into our upper atmosphere, the two storms were labeled as a G2 and G3 solar storm, on a scale of G1-G5, much like a hurricane scale of damage and strength. So, one was fairly benign and the other was a bit stronger. Even still, no major electrical or satellite disruptions ultimately occurred from the event.

What did take place however was an impressive northern lights show, known as 'aurora borealis'. Typically, to see the night sky light up with a spectrum of varying colors, while spectacular, is limited for viewing only by those living close to the Earth's magnetic poles. So, generally folks in Alaska and parts of upper Canada are exclusively able to partake. But, when a solar storm hits Earth, a wave of magnetic/electrical energy intensifies and briefly energizes the poles, extending the visual effect even further south.

To clarify why this would happen, here's Vox explaining what an aurora is: An aurora occurs as the charged particles from the sun travel along the Earth's magnetic field in the upper atmosphere and collide with gas atoms, causing them to emit light. They appear fairly often in places like Alaska or Iceland, but it takes a strong storm to get auroras this far south.